High school is trying to push legal actions due to the use of VPNs (MI)

My high school recently blocked all use of most platforms on their wifi, including apps that are needed for school use. Additionally, the school has a majority of the area without service for most phone providers. To circumvent this, a large amount of students in the school (100+ students) began using VPN’s on the school’s wifi. After the school noticed this, they fought back by blocking most VPN’s and finding ways to kick off anyone using one.

Today, a few announcements were made by some of the teachers in technology classes, etc.. They said that anyone who used a VPN risked legal trouble and that it was considered hacking to bypass the school’s internet blocks. Where do we stand here? I looked through the student technology acceptable use form that we were required to sign at the beginning of the year, and nowhere does it state that we’re prohibited from using VPN’s on school wifi. Additionally, it doesn’t say anything about bypassing the filter they have set up on the wifi.

Is there anything they can actually do about this, and if so, what can we do to fight it if they proceed with legal actions?

Edit; Thank you to those who responded. Looks like there’s not much we can do about most of this.